Carbon nitrides have interesting mechanical, optical, and tribological properties. These super-hard diamond-like materials have low densities, are extremely wear resistant, and are generally chemically inert. Carbon nitrides are used in biocompatible coatings for medical implants, battery electrodes, gas separation systems, corrosive protection, humidity and gas sensors, and other applications. The applications for carbon nitrides generally depend on particle size and texture and on the relative nitrogen content of the carbon nitride.
An extensive effort has been focused on the synthesis of precursors and the development of methods to control the size, regulate the texture, and increase the nitrogen content in carbon nitrides.
There have been recent reports describing the use of energetic “high-nitrogen” compounds for preparing carbon nitrides. High-nitrogen compounds are a relatively new class of energetic compounds whose energy is largely derived from their very high positive heats of formation that result from the large number of energetic N—N and C—N bonds in these compounds. SCHEME 1 shows the formulas of three high-nitrogen compounds (DAAT: 3,3′-azobis(6-amino-1,2,4,5-tetrazine); BTATz: 3,6-bis-(1H-1,2,3,4-tetrazol-5-ylamino)-1,2,4,5-tetrazine; and TAG-AT: triaminoguanidinium 5,5′-azobis(1H-tetrazolate)) and their associated heats of formation.

High-nitrogen compounds that contain polyazido groups possess even higher heats of formation. In general, however, compounds with polyazido groups are extremely sensitive to spark, friction, and impact (H50) and generally exhibit poor thermal stability. Therefore, applications for these types of compounds tend to be limited. Gillan, however, has reported the preparation of carbon nitrides C3N4 and C3N5 from 2,4,6-tri(azido)-1,3,5-triazine [1]. The formulas of 2,4,6-tri(azido)-1,3,5-triazine and another high-nitrogen compound having polyazido groups are shown in SCHEME 2 below, along with some data related to their melting points, decomposition temperatures, heats of formation, and sensitivities to spark, friction, and impact.

Other reported preparations of carbon nitrides using other types of precursors generally involve applied pressure, high temperature and/or shock compression, and the products obtained are often nitrogen poor materials that are occasionally contaminated with hydrogen-containing by-products [2–8].
High-nitrogen compounds with better thermal stability and less sensitivity to spark, friction, and/or impact than known precursors would be better precursor materials for carbon nitrides.
There remains a need for better precursor materials for carbon nitrides.
Accordingly, an object of the present invention is to provide better high-nitrogen compound precursor materials for preparing carbon nitrides.
Another object of the present invention is to provide a method for preparing carbon nitrides from high-nitrogen compounds.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.